Pump



March 31,1931. D. J. CQQANT PUMP 2 Shets-Sheet l Original Filed Feb. 15,1926 FIGURE .1

rleune 2 FIGURE F IQURE 5 INViHTOH ATTQRNEY March 31, 1931. D, J CONANT1,798,787

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Original Filed Feb. 15, 1926 2 Sheets-Sheet; 2

y FIGURE 6 ATTORNEY Patented Mar. 31, 1931 DAVID J. CQNANT, 0F MEMPHIS,TENNESSEE PUMP Continuation of application Serial No. 88,327, filedFebruary 15, 1926. This application flled December 15, 1927. Serial No.240,316.

In the construction of centrifugal pumps it is common practice to mountthe impellers upon a round steel shaft by means of the ordinary gib-headkey. In this construction it is necessary to provide a suflicientlylarge bore in the impeller to permit the shaft to slide freelytherethrough, and consequently Also when the load of driving is appliedthe force acting upon the driving shaft will urge it into contact withthe impeller upon one side of the key with a corresponding separationfrom the impeller upon the opposite side of the key thereby creating aneccentric relationship between the driving shaft and impeller.

This oflsetting of the impellerrelative to the shaft on which it ismounted obviously unbalances the impeller so that balancing of the sameis required after the impellers are mounted on the shaft. Also, sincethe impeller is offset relative tothe shaft it is also offset relativeto the axis of the neck of the bowl in which it operates. It isnecessary,

therefore, to provide a bowl having a neck somewhatlarger than theimpeller to permit the free rotation of the impeller therein.

Because of this somewhat eccentric mounting of the impeller on the shaftconsiderable hand fitting is required in assembling the parts, andnonsinterchangeable parts must be used. Furthermore, in thisconstruction the shaft should be of steel to carry the load andconsequently will rust in the water being pumped. When rusted, the Wholeshaft must be replaced.

It is one object of my invention to provide a construction wherein theabove men tioned difficulties may be satisfactorily over-- come and theimpellers accurately and concentrically mounted in the several bowls andso maintained in concentric relation thereto regardless of whether ornot the shaft is concentric with the impellers, thereby eliminating thenecessity of subsequent balancing and hand fitting as now required,,or,in other words, to provide a journal surface for the impeller to rotateupon that is entirely separate from the driving means and which willmaintainits concentric position with the impeller whether or not thedriving shaft is concentric with the impeller.

It is another object of the inventionto provide a structure wherein thepump bowl neck may be made in its normal size and still provide therequired clearance between it and the impeller, whereby to reduceleakage.

It is still another object of the invention toprovide a structurewherein a non-corrosive material may be used for that portion of theshaft carrying the impellers and wherein the impellers may be mounted onthe shaft withoutthe use of a key if so desired.

Finally it is an object of the invention to provide a structure of thecharacter indicated wherein a means is provided'for spacing the severalimpellers and supporting the same, and closingthe supporting shaft offfrom the water being pumped so that materialfor the shaft such as steelmaybe used. without danger of corroding.

. In the drawing: 7

Figure 1. is a longitudinal section through a pump structure embodyingmyinvention. FigureQ is a section on line 2.2 of

Figure 1. a

Figure 3 is a section on line 33 of Figure 1. y

Figure 4 is a sectional view through a portion of a pump structureshowing another embodiment of my invention.

Figure 5 is a detail illustration showing a means for securing apositive driving connection between the sleeve and impeller.

Referring more particularly to the drawing, I show at 1 a portionof ashaft hexagonal in transverse cross-section, having one end upset-as at2 and the other end cylindrical in form as at 3 and threaded as at 1 and5.

At 6 I show an impeller broached as at 7 to engage the shaft part 1, andhaving annular shoulders formed in each end thereof and concentricallypositioned relative to its axis of rotation as shown at 8 and 9respectively.

Between each two impellers is shown a sleeve 10. This sleeve 10 issomewhat larger than the shaft part 1 and completely encloses the same,and fits snugly into the opposing shoulders 8 and 9 of the twoimpellers. A sleeve 10 is also shown inserted between the g upset end 2of the sliaft part1 and theshoulder 80f the lowermost impeller-{andanother sleeve 10 is shown mounted upon the uppermost impeller. On thisupper sleeve 10 is seated'a nut 11 which is screwed into place on thethreaded part 3 of the shaft.

It'may now be clearly seenthat by providingsleeves 10 of uniformlength-the impellers and sleeves are each interchangeable and may beassembled as "they come to hand, and merely slipped on to the shaftwithout the use of a key of any kind. The impellers and shaft must ofnecessity rotate as a unit, and they are securely bound together withthe sleeves on the shaft by the upset end '2 on shaft part 1 and thelocknut 11, this binding together of the impellers and sleeves effectinga positive driving connection between them.

In the construction hereinbefore described rotation of the impeller, butit need not be oversize as in the pumps heretofore constructed.

Since it is, in practical work, necessary to I provide some littlespacing between the impeller and the drive shaft in order-to render theimpeller slidable on the drive shaft, it

necessarily follows that although the shaft and impeller may beconcentric when at rest, when a polygonal shaft of the type described isused, this concentric relationship is immediately destroyed when poweris applied to the shaft since it is of necessity forced into contactwith the impeller hub at one point and away therefrom at another.

Since the water is entirely shut off from the shaft part 1 it iseffectually prevented from rusting, and consequently provides a durableconstruction.

In the embodiment shown in Figure 4 it is shown that this constructionmay also be used witha round shaft'if so desired'by using opposite sidesof the key. If a key is driven in in such a manner as to secure a tightfit between shaft and impeller then an eccentric relation would be had,but the concentric relation of impeller and bowl would not be destroyed,because the impeller must run true in the journal surface provided inthe bowl neck 13. c

The sleeves 10 clearly perform several important functions. They spacethe several impellers to which they may be secured in any suitablemanner. They protect the shaft from the corrosive action of the waterbeing pumped. They maybe made of non-corrosive material and theyfunction as bearings. But their most important function is to cooperatewith the bearings and the bowls to maintain the impellers in concentricrelation to the bowl necks irrespective of the exact relationbetween'the shaft-and the impellers. This desired cooperation can onlybe secured, of course, if a correct driving connection is establishedbetween the sleeve and impeller. This connection may be securedasdescribed, or inother ways such as notching the sleeve as at 16 andproviding a key 17 long enough to engage the notches. The engaging notchand key construction 1617 is preferably used merely to prevent slippagebetween the impeller and sleeve.

I It is to be understood, of course, that while bly and operation may bemade within the."

I claim: I y

1. In combination, a pump bowl having a bearing therein, a: sleeverevolubly mounted inthe bearing, a-drive shaft passing through thesleeve in spaced relation thereto, animpeller revolubly mounted in thebowl in axial alignment with the sleeve, 9. driving and aligningconnection between the impeller and sleeve, and driving means insertedbetween the impeller and shaft.

2. In combination, a pump bowl having a bearing therein, a sleeverevolublymounted in the bearing, a driveshaft passing'through the sleevein spaced relation thereto, an impeller revolubly mountedin the bowl inaxial alignment with the sleeve and having a 'recess formed in the endthereof in concentric relationto its axis of rotation, one end of theadj acent sleeve 'being' fitted into said recess scopeof the appendedclaims.

DAVID J. CONANT.

